Calluna plant named ‘Nr 580’

ABSTRACT

A new cultivar of  Calluna vulgaris , ‘Nr 580’, characterized by its upright plant habit, its bud flowering habit imparting a long flowering period, its densely packed clear white flower buds, its vigorous growth habit, and its cold hardiness to U.S.D.A. Zone 4.

Botanical classification: Calluna vulgaris.

Variety denomination: ‘Nr 580’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Calluna vulgaris and will be referred to hereafter by its cultivar name, ‘Nr 580’. ‘Nr 580’ is a new cultivar of evergreen shrub grown for use as a landscape plant.

The new Invention arose as the result of an ongoing controlled breeding program by the Inventor in Wezep, The Netherlands. The goal of the breeding program is to develop new cultivars of Calluna that combine an upright growth habit and flowers that exhibit strong, bright colors with a bud flowering habit. ‘Nr 580’ was selected as a single unique plant by the Inventor in September 2005 in a test garden in his nursery in Wezep, The Netherlands. ‘Nr 580’ arose from a cross made in September 2003 between a proprietary female parent designated by accession No. K23618 and a proprietary male parent designated by accession No. 23E27 (both unnamed and unpatented).

Asexual reproduction of the new cultivar was first accomplished by the Inventor using stem cuttings in September of 2005 in Wezep, The Netherlands. The characteristics of ‘Nr 580’ have been determined to be stable and are reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent the characteristics of the new cultivar as grown outdoors in trial beds and containers in Wezep, The Netherlands. These attributes in combination distinguish ‘Nr 580’ as a unique cultivar of Calluna.

-   -   1. ‘Nr 580’ exhibits an erect, upright growth habit.     -   2. ‘Nr 580’ exhibits stems that are densely covered with flowers         that are clear white in color.     -   3. ‘Nr 580’ exhibits a bud flowering habit, which imparts a long         flowering period.     -   4. ‘Nr 580’ exhibits a vigorous growth habit.     -   5. ‘Nr 580’ is cold hardy to U.S.D.A. ZONE 4.

‘Nr 580’ differs from both its parent plants in having a more erect flowering habit and in having more densely packed flowers. The closest comparison cultivars for ‘Nr 580’ are cultivars from the same breeding program that are similar in plant and flowering habit, ‘Nr 5163’ (U.S. Plant patent application Ser. No. 12/284,556) and ‘Nr 5157’ (U.S. Plant patent application Ser. No. 12/284,504). ‘Nr 5163’ differs in having flowers that are red-purple in color while ‘Nr 5157’ differs in having flowers that are pink-purple in color. ‘Nr 580’ can also be compared to Calluna vulgaris var. alba erecta (not patented). ‘Nr 580’ is unique from var. alba erecta in that var. alba erecta has a less upright plant habit with less flowers that open. The flowers of ‘Nr 580’ remained closed (bud flowering) and therefore ‘Nr 580’ blooms for a longer period of time.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying colored photographs illustrate the overall appearance and distinct characteristics of a 2 year-old plant of the new Calluna as grown outdoors in a 10 cm container in Wezep, The Netherlands.

The photograph in FIG. 1 illustrates the overall appearance of ‘Nr 580’ in bloom.

The photograph in FIG. 2 provides a close-up view of the flowers of ‘Nr 580’.

The photograph in FIG. 3 provides a close-up view of the foliage of ‘Nr 580’.

The Colors in the photograph may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new Calluna.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of 2 year-old plants of the new cultivar as grown outdoors in 10 cm containers in Wezep, The Netherlands. The plants were grown with an average day temperature of 14° to 30° C. and an average night temperature of 5° to 15° C. under ambient light. The phenotype of the new cultivar may vary with variations in environmental, climatic, and cultural conditions, as it has not been tested under all possible environmental conditions. The color determination is in accordance with the 2001 RHS Colour Chart of The Royal Horticultural Society, London, England, except where general color terms of ordinary dictionary significance are used.

-   General description:     -   -   Blooming period.—Blooms from late summer into early fall in             Wezep, The Netherlands.         -   Plant habit.—Densely foliaged and flowering, upright,             evergreen shrub.         -   Height and spread.—Reaches about 21.5 cm in height and 24.3             cm width (2 year-old plant).         -   Hardiness.—Cold hardy to U.S.D.A. Zone 4 and withstands             temperatures of at least 35° C.         -   Diseases resistance.—No particular resistance or             susceptibility has been observed.         -   Root description.—Fine. -   Growth and propagation:     -   -   Propagation.—Stem cuttings.         -   Root initiation.—Roots develop in about 20 days in summer             (30 days in spring) under greenhouse conditions with ten the             first 10 days under plastic.         -   Growth rate.—Vigorous. -   Stem description:     -   -   Stem shape.—Round.         -   Stem strength.—Strong.         -   Stem color.—152A.         -   Stem size.—Lateral branches are an average of 11.4 cm in             length and 2 mm in diameter.         -   Stem surface.—Slightly glossy and densely covered with very             short, fine hairs.         -   Stem aspect.—Nearly upright to main stems.         -   Internode length.—Average of 2 mm.         -   Branching.—Freely branched from base with 10 main stems with             an average of 11 lateral branches per main branch. -   Foliage description:     -   -   Leaf shape.—Oblong.         -   Leaf division.—Simple.         -   Leaf base.—Decurrent.         -   Leaf apex.—Obtuse.         -   Leaf fragrance.—None.         -   Leaf venation.—None visible.         -   Leaf margins.—Entire and sparsely covered with very short,             fine hairs.         -   Leaf arrangement.—Opposite.         -   Leaf attachment.—Sessile.         -   Leaf number.—About 114 per lateral branch.         -   Leaf surface.—Glabrous and slightly glossy on upper and             lower surface.         -   Leaf size.—Average of 1.5 mm in length and 0.5 mm in width.         -   Leaf color.—Newly expanded leaves upper and lower surface;             143A to 143B, mature leaves upper and lower surface; 137A. -   Inflorescence description: (Flower descriptions refer to mature     flower buds)     -   -   Flower type.—Solitary and arranged in small clusters             (average of 6) of flower buds borne at the leaf axils,             flowers remain in the bud stage and do not open.         -   Flower fragrance.—None.         -   Flower Lastingness.—Average of 4 weeks, self cleaning.         -   Flower bud description.—Immature; ovate in shape, an average             of 3 mm in length and 1.8 mm in width, glabrous surface,             155C in color.         -   Flower quantity.—Average of 150 per lateral stem, over             15,000 per plant (2 years in age).         -   Flower aspect.—Held outward to upright.         -   Flower shape.—Ovate.         -   Flower size.—An average of 4 mm in depth and 2 mm in             diameter.         -   Peduncles.—Average of 2 mm in length and 0.5 mm in diameter             with an average angle to stem of 45°, 144A in color,             moderate in strength, surface glabrous.         -   Pedicels.—None.         -   Calyx form.—Rotate in form, average of 1 mm in length and 2             mm in diameter.         -   Sepals.—5, average of 1 mm in length, 0.5 mm in width,             broadly ovate in shape, entire margin, rounded apex, cuneate             base, surface is smooth and dull in appearance, color of             inner and outer surface 143A when bud is immature, 137A when             bud is mature.         -   Petals.—5, only outer surface is visible as they remain             closed, about 4 mm in length and 1.4 mm in width, ovate in             shape, entire margin, bluntly acute apex, surface is velvety             and glossy in appearance, color when first showing color,             both surfaces; 155C, color mature, both surfaces; 155B to             155C, non-fading. -   Reproductive organs:     -   -   Stamens.—None present, flowers are pistillate.         -   Pistils.—1, about 3 mm in length, stigma is club-shaped and             145C in color, style is an average of 2.8 mm in length and             145C with base 145A to 145B in color, ovary is 143A in             color.         -   Fruit and seed.—None have been observed to form. 

1. A new and distinct cultivar of Calluna plant named ‘Nr 580’ as herein illustrated and described. 